Destiny Says So
by Rosawyn
Summary: Tony is curious about Bruce's soul-mark, if he's found his soulmate yet. And of course there's also the matter of Tony's own soul-marks. (Fic 1 in "Fingerprints and Soul-scars")


**Destiny Says So**

As Bruce leaned his dark curly head over the microscope, Tony's eyes fell on the warm amber soul-mark on the back of Bruce's neck. "Hey, you, uh, you found your soulmate yet?" Tony asked. Bruce hadn't mentioned it, but most of their conversations had been about science, snack food, or saving the world. Too much of that last one, honestly, for much 'normal' conversation—whatever that was, anyway—to have a chance yet.

Bruce glanced up, smiling in his bashful way. "Nah, not yet. I've never had my mark analyzed or anything, but it's pretty large, you know? Betty said it looked like it must be a man." He laughed softly, looking down.

"Would that be a problem for you?" Tony leaned against the lab table, watching Bruce curiously. He had heard of cases where one or both people, despite clear match evidence, balked at the sex of their soulmate. It wasn't a system without its flaws, apparently, but it was also a system Tony itched to understand. Of course, he'd been told since he was a small child that it wasn't strictly a biological or scientific mechanism, since it was more to do with this 'soul' business that couldn't truly be measured. Studying soul-marks had been a hobby of his father's, and sadly Howard's research was probably still the most comprehensive body of work on the subject. Maybe it was all a cosmic joke, and humanity had been interpreting the odd little fingerprint marks wrong throughout all of recorded history. Maybe they meant nothing at all and only 'worked' as self-fulfilling prophecies.

"No, not really." Bruce ducked his head. "I've just never met many guys I was attracted to, you know? So it just feels a bit odd, knowing I'm supposed to be with one."

"Or, a woman with rather large hands," Tony supplied helpfully.

Bruce grinned at him, laughing softly again. "Or that."

"Yeah, well, you should see mine." Tony grinned crookedly and turned, pushing his dark curls up with one hand and tugging the collar of his t-shirt down with the other to make sure the marks were fully visible. "I mean, I have _two_, and if that wasn't weird enough..." It's not that triads were unheard of, but they were still rare. Odd. Not exactly expected. "I mean, the one is just..."

"Oh." The word was more of an exhalation than anything.

"...huge," Tony finally finished. All the blood drained from his face—a decidedly odd sensation. He knew someone with fingers that large, probably the only being alive who _could_ be a match. He whipped around, staring sharply at Bruce who was backing away and looking far more terrified than Tony felt—honestly, Tony was feeling a lot of things in that moment, and terror was only a small fragment, inconsequential really.

Bruce tore his eyes away from Tony's face, dropping his gaze to the floor. He stuck both of his hands into the pockets of his lab coat. "I should..."

"Bruce?" Tony's brow furrowed in confusion. "Hey, come on." He took a step towards Bruce, hands out at his sides to show he was unarmed, not a threat.

Bruce shook his head, still refusing to look at Tony. "You don't want—this isn't a good idea, Tony."

Tony grinned. "See that's where you're wrong; of course I want to know. I have to know. It's, like, a science thing."

Bruce's gaze flickered up to Tony's face then, complete with a tiny flicker of a smile that had Tony's heart constricting in a way he was pretty darn sure it had never constricted before, no matter how endearing Bruce's smiles had always been. And, no, he couldn't be doing this until he _knew_, damnit. But Bruce looked back down, hunching his shoulders. "Sometimes, I think it's better not knowing."

Bruce had managed to back himself against a wall—perhaps he'd been aiming for the door and missed—so Tony sat on a lab stool and shoved one hand through his hair while he looked at him. "Maybe," Tony conceded. "But I guess I've never been very good with caring about what's good for me." He sighed. "Look, I know I'm not exactly the kind of person most people dream of in a soulmate, but...well, I'm rich, and that has to count for something." Maybe most people didn't like to admit it, but everyone liked money. "Also we do the science thing together, so that's a plus, at least from where I'm sitting." He gestured expansively with one arm. "I could even show you a list of all the 'sexiest man alive' and 'most eligible bachelor' lists I've been on, or the considerably shorter list where I was at the top..." He blew out air though his lips, shifting a bit on the stool. "It wouldn't be so bad, is what I'm trying to say. I'd be willing to try—to make this work—if it's a match, if we're a match." Tony bit the inside of his cheek. Why did it matter so much? It's not like he'd cared about the soulmate thing before, beyond the frustrating desire to understand something that defied logic.

"Tony, that's not—" Bruce looked at him with a pained expression, eyes filled with gentleness that had Tony's heart constricting once again. He shook his head, shoving his hands deeper into his pockets. "I'm not the one who'd be getting a raw deal here."

"What?" Tony couldn't help the incredulous smile that leapt onto his face. "You think that—that anyone with eyes and sense wouldn't want you?" He shook his head, disbelieving. "You're brilliant—and hot as hell. And I'm not scared of 'The Other Guy,' either." He waggled his fingers dismissively. "He likes me, remember? Saved my life and everything." He slid off the stool and took a careful step towards Bruce again. "Can we just...try? I mean, I know it won't mean anything if there's no reaction, because they don't always react, but we can do the analysis then and know for sure, but...I just wanna try this. Okay?"

Bruce let out a sigh, his shoulders relaxing almost like a balloon deflating. He nodded. "Okay. Yeah. I mean, might as well know for sure, right?" He didn't quite meet Tony's eyes.

Tony walked closer, reaching out and putting his hand carefully on Bruce's bicep. "Mind if I try first?"

Bruce shook his head, turning ninety degrees so Tony could see the amber fingerprint once again. It looked about the right size. Tony gently brushed his fingers across it, grinning broadly as it changed colour at his touch. "Wow," he breathed. "Are you getting any sensory reactions? Because there's definitely a colour one here."

Bruce squeezed his eyes shut, swallowing. "Yeah, it's kind of...throbbing. Not actually—not painful—um, it's kind of...soothing. What—" He turned his head to look at Tony. "What's the colour?"

Tony's grin was impossibly broad. "Green, Bruce; it turns green."

Bruce let out a choking laugh that may have included a sob. "Are you serious? That's—you're not kidding?"

"I can take a video of it if you want," Tony offered. He had his phone in the pocket of his jeans. Shades of brown, yellow, orange, and red were more common for colour changes, but blues, purples, and greens weren't exactly abnormal either.

Bruce laughed, more relaxed. "I think I'll want to see that later, yeah. But..." His brow furrowed, thoughtful. "So we know, I mean, that's it. Did you—did you still want me to touch yours?"

"Hell yeah." Tony smiled crookedly. "I mean, you touching me is awesome, just, _because_, but...I want to know if mine reacts, you know? For science." He waggled his eyebrows.

Bruce nodded, laughing a bit again. "Okay, sure." As Tony turned around to give Bruce full access to the back of his neck, Bruce muttered, "You sure know what to say to me, don't you?"

Tony was grinning so hard it almost hurt. This was why Bruce was perfect: the one thing he and Bruce had known right from their first meeting was how to talk to each other. And then he felt Bruce's fingers brushing across his skin, and...wow. That was...well, okay, it was kinda weird. "Colours?" he asked; that was more important, since it was provable, observable.

"Yeah." Bruce sounded a little surprised, and rightly so, since it was reasonably uncommon for both people to have colour changes. "The—the small one, mine, it's kinda going red, like not exactly a flashy red like the Iron Man suit, but reddish. The other one's not...but I wouldn't really expect it to, I guess. But, um, sensory reactions?"

"Yeah." Tony huffed out a laugh. "From both of them, actually. The smaller one is warm, like, in the nicest way—really lovely, and I'd be happy if you just kept touching it forever, actually." He grinned again. "But the big one's _itchy_."

Bruce pulled his hand away. "Sorry."

"No, don't be sorry." Tony turned around to face him again, catching him by the chin and tilting his face up to meet his eyes. "It's fascinating; that's one of the rarest reported sensory reactions. I suppose most would say, _thankfully_, since it's not exactly the most pleasant." Tony nodded his head from side to side, grimacing thoughtfully. He moved his hands to take Bruce by the biceps. "But it probably would feel different...you know, if it was the other you."

Bruce's grin was both awkward and nervous. "That's not...you don't..."

"Oh, it's definitely something I want to test, to try out." Tony rubbed his thumbs against the white material of Bruce's lab coat, hoping it felt soothing to Bruce. "But when you're okay with it. It doesn't have to be... I can be patient."

Bruce nodded a little jerkily, but his eyes showed his relief. "What—uh—" Bruce looked away, a nervous smile on his lips, then looked back. "We know, so...what do we do now?"

Tony bit his lip thoughtfully. "When you said you hadn't met many guys you found attractive, was I one of the lucky ones?"

"Yeah." Bruce smiled, warm with beautiful little crinkles around his eyes. "You're one of the lucky few."

Well, that was good. Great, actually. "Then I'd like to kiss you if that's okay."

Bruce's hand slid around the back of Tony's neck, triggering the dual sensations from his soul-marks once again as Bruce—somewhat shockingly—pulled him down into a kiss.

Tony kissed him back with all his practiced skill, still somehow feeling more nervous than he had for his first kiss, back when he was fifteen—the other person hadn't mattered then; he didn't even remember her name. Bruce mattered, though, so Tony wanted it to be good, and not just because they were soulmates, because Bruce had _always_ mattered.

Bruce broke the kiss, pressing his forehead to Tony's and whispering, "You don't really understand what you're getting into here, Tony. What if—what if it's too much?"

Tony made a dismissive sound, shoulders twitching in a small shrug. "I can handle it." He grinned. "Destiny says so."

Bruce chuckled. "Right, because you suddenly believe in destiny?"

Tony laughed, wrapping his arms more firmly around Bruce's back and holding him close. "I suspect I'm actually just over-confident, but...this _feels_ right. And—" He pulled back a bit so he could look Bruce in the eye. "All the reactions—colour and sensory for both of us—maybe it's a good sign? Like, super-high compatibility? There have been theories proposed..." Nothing anyone had ever proved, but...

Bruce's smile was warm, his eyes soft. "You want to believe."

"I want to do this one thing right," Tony countered. "You deserve it." He kissed Bruce's nose. "So yeah, I want to believe I'm capable of not screwing this up."

"If it helps," Bruce said, rubbing his fingertip over the smaller mark on the back of Tony's neck, "I believe you are."

It did help. It helped a lot.

o0o

**So I got this idea for a soulmates AU (and I'm pretty sure it's unique with the whole fingerprints thing) and now it's kind of eating my brain, so this will be the first in a series of at least three oneshots about various Marvel characters finding their soulmates.**

o0o


End file.
